https://devzone.nordicsemi.com/f/nordic-q-a/105017/booloader-stopped-working-after-upgrading-from-ses-7-10-to-ses-7-12Hello. I&#39;m not able to use DFU (Android Version) After SES updade. I&#39;m getting an &quot;X&quot; in DFU initialization step. I was using SES 5.7, when I migrate to 7.32 this issue started. So I download all SES versions to check wich version was the problemen-USTelligent Community 13Wed, 25 Oct 2023 14:45:18 GMThttps://devzone.nordicsemi.com/thread/452326?ContentTypeID=1Wed, 25 Oct 2023 14:45:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7b35f058-b57c-41b0-8399-6b3212fee268Hermano Guimaraes<p>Thanks Kenneth</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/452196?ContentTypeID=1Wed, 25 Oct 2023 09:24:31 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9c20fb00-c913-4a06-9005-b7dd18d39fe4Kenneth<p>Hello,</p> <p>For new development you should be using nRF Connect SDK, see Note:<br /><a href="https://infocenter.nordicsemi.com/topic/struct_sdk/struct/sdk_nrf5_latest.html">https://infocenter.nordicsemi.com/topic/struct_sdk/struct/sdk_nrf5_latest.html</a>&nbsp;</p> <p>But to answer your question, when working with nRF5 SDK you should use the specific version described in the specific nRF5 SDK release notes:<br /><a href="https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/index.html">https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/index.html</a></p> <p>The following toolchains/devices have been used for testing and verification:<br /> <br /> - ARM: MDK-ARM version 5.25 <br /> - GCC: GCC ARM Embedded 9.2020-q2.major<br /> - IAR: IAR Workbench 7.80.4<br /> - SES: SES 5.42a</p> <p>Kenneth</p><div style="clear:both;"></div>